The immense black hole at the center of Radio Quasar RACS J032021.44-352104.1 (shortened to RACS J0320-35) is currently expanding at one of the fastest rates ever recorded.
Artist illustrations and x-ray images from Chandra for Racs J0320-35. Image credits: NASA/CXC/INAF-BRERA/IGHINA et al. / SAO / M. WEISS / N. WOLK.
The black hole residing in RACS J0320-35 has a mass approximately 1 billion times greater than that of the sun.
This system is situated about 12.8 billion light-years away from Earth, meaning astronomers are observing it as it existed just 920 million years after the universe’s inception.
It emits more X-rays than any other black hole identified in the universe’s first billion years.
Black holes are the driving force behind what scientists refer to as quasars.
This luminous giant’s energy is fueled by the significant amount of material that falls into the black hole.
The same research team discovered this black hole two years prior, but further observations from Chandra were required in 2023 to gain more insights.
Data from X-ray observations suggests that this black hole is expanding at a rate that exceeds the typical limits for such objects.
“It was somewhat surprising to observe such a dramatic growth in this black hole,” commented Dr. Luca Idina, an astronomer at the Harvard & Smithsonian Center for Astrophysics.
As material is drawn towards the black hole, it heats up and generates intense radiation across a wide spectrum, including X-rays and optical light. This radiation creates pressure on the infalling material.
Once the falling speed reaches a critical threshold, the radiation pressure counterbalances the black hole’s gravity, making it usually impossible for material to fall inward more rapidly. This upper limit is known as the Eddington limit.
Researchers believe that black holes growing slower than the Eddington limit must originate with solar masses exceeding 10,000, allowing them to achieve a mass of 1 billion solar masses in the early universe.
Such massive black holes may originate from unique processes, often linked to incredibly dense clouds of gas that contain heavier elements than helium.
Interestingly, RACS J0320-35 is expanding at a remarkable speed, estimated to be 2.4 times greater than the Eddington limit, indicating that its formation may have followed a more typical path, beginning with a mass of less than 100 solar masses resulting from massive star explosions.
“By determining a black hole’s mass and growth rate, we can infer its initial size,” said Dr. Alberto Moretti, an astronomer at INAF-Osservatorio Astronomico di Brera.
“This calculation permits us to evaluate various theories regarding the formation of black holes.”
To investigate how rapidly this black hole is growing (at rates between 300 and 3,000 solar masses per year), researchers compared the theoretical model with Chandra’s X-ray spectra, assessing the X-rays emitted at various energy levels.
The findings indicated that Chandra’s spectrum closely matched their expectations based on a model for black holes developing beyond the Eddington limit.
Supporting data from optical and infrared observations further corroborates the conclusion that this black hole is accumulating mass faster than the Eddington limit permits.
“How did the universe generate the first generation of black holes?” mused Dr. Thomas Connor, an astronomer at the Harvard & Smithsonian Center for Astrophysics.
“This is one of the most pressing questions in astrophysics, and this singular object propels our quest for answers.”
Moreover, this research also sheds light on the origins of the jets of particles emitted by some black holes that approach the speed of light, as observed in RACS J0320-35.
“Jets like these are uncommon in quasars, suggesting that the accelerated growth of black holes may play a role in the formation of these jets,” the author remarked.
Their paper is set to be published in the Astrophysical Journal.
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Luca Idina et al. 2025. X-ray investigation of the possibility of Super Eddington accretion in a wireless loudsal of Z = 6.13. apjl 990, L56; doi: 10.3847/2041-8213/aded0a
Source: www.sci.news
